关键词: 枣, 花芽分化, 花发育, 内源激素

Abstract: In order to reveal the formation and regulation mechanism of jujube（Ziziphus jujuba Mill.）flower，we chose‘Qiyuexian’jujube to study its formation process and endogenous hormones changes. The flower forming process was observed by standard light microscope，scanning electron microscope and stereoscope. The endogenous hormones content was determined by liquid chromatography-tandem mass spectrometry（LC–MS/MS）. The results showed that the jujube flower formation contained flower-bud differentiation and floral development. The single bud differentiation taking 11 days was divided into six stages，vegetative stage，initial stage，sepal differentiation，petal differentiation，stamen differentiation and carpel differentiation. Floral development went through seven stages，bud period，bud split，sepal spread，petal spread，stamen spread，filament wilting and ovary inflated. IAA content dropped slowly after a quick decrease in fruit-bearing shoots（FBS），while it fell rapidly again after a sharp rise in flowers.ABA content had a significantly rise firstly and then decreased slowly at 5 cm of FBS，and it was similar to IAA in flowers. GA3 always remained at a low level，with the opposite tendency in FBS and flowers. Based on the results above，it is concluded that lower IAA，IAA/GA3 and higher ABA，GA3，ABA/GA3 and ABA/IAA were needed in flower bud incubation stage. In flower stage，it required high levels of IAA，ABA，ABA/GA3 and IAA/GA3，while relatively lower levels of GA3 and ABA/IAA. Our study reveals the formation and regulation mechanism of jujube flower which will provide guiding information for jujube flower management.

Key words: jujube, flower-bud differentiation, flower development, endogenous hormone